CSA/ANSI LNG 4.1-2018 Liquefied natural gas (LNG) dispensing systems for natural gas vehicles (NGV).
All field connections shall be plugged, capped, or otherwise sealed by the manufacturer prior to shipment to prevent entrance of foreign materials.
LNG and boil-off gas confining parts shall have a maximum working pressure (MWP) of not less than the pressure at which the safety relief device protecting that system, or subsystem, is activated.
A dispensing system shall be designed to provide effective grounding when attached to the vehicle as
a) the hose assembly shall be conductive (see Clause 7.10.); and
b) a grounding cable shall be provided with one end attached to the dispenser frame and other end provided with a clamp for attachment to the fuel tank grounding stud (see Clause 7.11).
A manual release valve shall be inaccessible to the public, and shall be protected by a locking
mechanism or permanent enclosure.
A manual operation at the dispenser shall be required to enable fuel flow. The controls for manual
startup of the dispenser shall be located or orientated so there is no possibility of accidental actuation.
Switches, valves, etc., that can be activated with the power off, and that can cause the system to
function as soon as the power is restored, shall not be used.
If more than one temperature fuel is available the grades (“warm,”“cold,” or both) shall be clearly marked on the dispenser. LNG flow to the vehicle shall occur only after selecting the desired grade.
A dispenser shall be protected against lightning strikes in accordance with American Petroleum Institute
Recommended Practice 2003.
A dispenser shall be designed with an LNG recirculation system providing means to achieve the required
operating temperature prior to dispensing LNG to the vehicle. Recirculation vapor shall be vented back
to the fuelling station and captured. Recirculation flow shall not be included in the dispensing
A dispenser shall be provided with a system for boil-off gas control. Boil-off gas shall be vented back to
the fuelling station and captured.
A dispenser shall provide a means to vent the vehicle fuel tank from excess pressure to the fuelling
station tank or to a vent stack if required.CSA/ANSI LNG 4.1 pdf download.